Just in the first two days of the sales period, online purchases netted $4.45 billion in the U.S.. Mobile devices accounted for a record of $1.5 billion, with $2.72 billion on Thanksgiving and $1.73 billion spent on BlackFriday.

IBM says Black Friday outpaced that with the average basket size of $134.45, and sales up 20.7% on a year ago with popular items including Apple Watch, Microsoft’s Surface Pro 4, and TVs from Samsung, Sony and LG.

The number of people buying goods online and by mobile during the holiday season continues to grow, but the average value of what they are buying may be falling. IBM says that Thanksgiving online sales — amassed by way of its Benchmark survey tracking thousands of sites — overall were up 26% compared to a year ago. But the average spend per order on Thursday as $123.45. That’s down from $125.25 a year ago, and nearly $10 less than 2013, when the average basket value was $132.

Adobe said that its $2.72 billion in estimated spend online on Black Friday showed growth of 14%. Adobe had expected growth of 19%.

Taken together, the numbers could indicate a couple of things. The first is that the bigger economic climate could be putting a chill on people’s spending, as some have predictedwould be the case. The other is that a bigger push to sell on Thanksgiving could be leading to slightly softer sales the day after.

Mobile is still not as popular as desktop for buying things, but it’s definitely growing, especially as a place to browse. Mobile accounted for 60% of all online traffic on Thanksgiving, IBM said, up 14.8% on a year ago; and it took 54.4% of traffic on Black Friday, up 16.6%. On Thanksgiving, 40% of all sales were completed on mobile devices, another rise compared to last year, when one-third of sales were made on smartphones and tablets. Black Friday saw 35.3% of sales on mobile, IBM said.

IBM also noted that on Black Friday, smartphone shoppers spent $117.87 on average per order, up 5% on last year. Interestingly, while tablets appear to be waning in popularity as a shopping device, the bigger screens and better experience are yielding essentially the same shopping cart value as a desktop purchase: just under $140.

Adobe said that 57% of traffic came from mobile devices on Thanksgiving, and while it may be seeing softer sales overall on Black Friday, mobile is going strong so far. Smartphones and tablets accounted for 34% of online sales on the second day. Consumers on iPhones accounted for 67% of all smartphone-completed purchases on Black Friday.

ComScore predicts that mobile will account for most of the growth in e-commerce holiday shopping this year, although starting from a significantly smaller base than desktop sales. IBM’s data backs this up.

For now, smartphones continue to be the “device of choice,” says IBM. They accounted for 46.7% of all shopping traffic, while tablets were only at 13.7%. Accordingly, IBM says smartphones drove more sales, too: 23.9% compared to tablets at 16.1%. This is as much a sign of what’s the most convenient device as the fact that tablets are simply not as popular as handsets. At the same time, smartphones’ screens have improved and grown dramatically, making them much more browser-friendly.

The day after Thanksgiving has traditionally been punctuated with a big rush to physical stores to snap up bargains for the holidays. Early reports, however, indicate thinner in-store crowds — a result of many top stores extending Black Friday opening hours to start the day before, but also the continuing shift to shopping online.

IBM predicts that Black Friday sales online will be up by 14.5% over a year ago, with popular tech items including sales of the .

Anecdotally, I saw a lot of people on Twitter and Facebook joking about turning on email filters to weed out over-promotion from various e-commerce companies, but Adobe notes that in fact email has proven to be a strong driver of traffic. 14% of all revenue on Thanksgiving, it said, was attributable to inbox promotions.

In terms of other marketing, Adobe notes that Amazon is edging out eBay on promotions on Black Friday, after eBay beat it out on Thanksgiving. Walmart has been less popular than Target but is “closing in” on its retail rival.